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Topic: When is the most critical time to control fermentation temps (Read 1792 times)

If memory serves, I believe that is is in the first 48-72 hours of pitching yeast. This is when they are most active in producing phenols, fusels, esters, etc., and if you want to minimize those, make sure to keep a 'leash' on the yeast by regulating the fermentation temp. I do this with a temperature controller probe insulated with styrofoam, duct-taped to the outside of the fermenter.

I ask the question because I only have room for two vessels in my fermentation chamber/lagering fridge. Currently, I have a California Common in there, and the yeast was pitched Saturday night @ 9pm (pitching + 84 hours at the moment) at 64 degrees. The yeast is actually Wyeast 2204 Bavarian lager.

I have a bit of an aggressive brewing schedule coming up. I am planning on brewing a hoppy american wheat tonight, THEN I am brewing an Oktberfest with my wife on Sunday. Bottom line, I need to have the Oktoberfest set to 50 degrees on Sunday, meaning that the ferm fridge will likely have a lower ambient temp.

My current plan is to brew the wheat tonight (estimated OG of 1.051), pitch a stepped-up US-05 starter (as I need a quick and vigorous fermentation, this wheat is going to be kegged in 12 days) at 66 degrees, then on Sunday (pitching + 4 days), remove the wheat, leave it in the basement (ambient temp of ~74 degrees) to finish up.

The only issue with this plan is that I would need to remove the California Common tonight, as if I tape the probe to the wheat, the freezer will likely get down really low to try to stabilize the fermenter temp AND I would need to do the same with the wheat to make room for the O-fest.

Clear as mud? I'm just trying to minimize unwanted esters, phenols, fusels, etc., and was hoping that I could let these fermentations go after a few days. Alternatively, I could rig up the <shudder> swamp chiller.

48 hours is pretty late into a ferment, especially if a proper pitching rate is used. I would say as early as 4 to 6 hours after pitching, the wort needs to be down in the desired fermentation temperature range. Most successful commercial brewers actually chill their wort to below the desired ferment temp and allow it to rise after the yeast is pitched.